Beyond the Stokes approximation: shallow visco-elastic ice-sheet models
Abstract The hypothesis that ice-sheet evolution is only controlled by the long-term non-Newtonian viscous behavior of ice has been challenged by observations indicating that effects like brittle failure, stick-slip sliding, tides and wave action may affect ice-sheet evolution on sub-daily timescale...
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Cambridge University Press (CUP)
2023
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Online Access: | http://dx.doi.org/10.1017/jog.2023.75 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143023000758 |
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crcambridgeupr:10.1017/jog.2023.75 2024-03-03T08:45:23+00:00 Beyond the Stokes approximation: shallow visco-elastic ice-sheet models Bassis, Jeremy N. Kachuck, Samuel B. Biological and Environmental Research National Aeronautics and Space Administration Division of Earth Sciences 2023 http://dx.doi.org/10.1017/jog.2023.75 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143023000758 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology page 1-12 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 2023 crcambridgeupr https://doi.org/10.1017/jog.2023.75 2024-02-08T08:41:06Z Abstract The hypothesis that ice-sheet evolution is only controlled by the long-term non-Newtonian viscous behavior of ice has been challenged by observations indicating that effects like brittle failure, stick-slip sliding, tides and wave action may affect ice-sheet evolution on sub-daily timescales. Over these timescales, the quasi-static-creep approximation is no longer appropriate and elastic effects become important. Simulating elastic effects in ice-sheet models over relevant timescales, however, remains challenging. Here, we show that by including a visco-elastic rheology and reintroducing the oft neglected acceleration term back into the ice-sheet stress balance, we can create a visco-elastic system where the velocity is locally determined and information propagates at the elastic wave speed. Crucially, the elastic wave speed can be treated like an adjustable parameter and set to any value to reproduce a range of phenomena, provided the wave speed is large compared to the viscous velocity. We illustrate the system using three examples. The first two examples demonstrate that the system converges to the steady-state viscous and elastic limits. The third example examines ice-shelf rifting and iceberg calving. This final example hints at the utility of the visco-elastic formulation in treating both long-term evolution and short-term environmental effects. Article in Journal/Newspaper Ice Sheet Ice Shelf Journal of Glaciology Cambridge University Press Journal of Glaciology 1 12 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
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Earth-Surface Processes Bassis, Jeremy N. Kachuck, Samuel B. Beyond the Stokes approximation: shallow visco-elastic ice-sheet models |
topic_facet |
Earth-Surface Processes |
description |
Abstract The hypothesis that ice-sheet evolution is only controlled by the long-term non-Newtonian viscous behavior of ice has been challenged by observations indicating that effects like brittle failure, stick-slip sliding, tides and wave action may affect ice-sheet evolution on sub-daily timescales. Over these timescales, the quasi-static-creep approximation is no longer appropriate and elastic effects become important. Simulating elastic effects in ice-sheet models over relevant timescales, however, remains challenging. Here, we show that by including a visco-elastic rheology and reintroducing the oft neglected acceleration term back into the ice-sheet stress balance, we can create a visco-elastic system where the velocity is locally determined and information propagates at the elastic wave speed. Crucially, the elastic wave speed can be treated like an adjustable parameter and set to any value to reproduce a range of phenomena, provided the wave speed is large compared to the viscous velocity. We illustrate the system using three examples. The first two examples demonstrate that the system converges to the steady-state viscous and elastic limits. The third example examines ice-shelf rifting and iceberg calving. This final example hints at the utility of the visco-elastic formulation in treating both long-term evolution and short-term environmental effects. |
author2 |
Biological and Environmental Research National Aeronautics and Space Administration Division of Earth Sciences |
format |
Article in Journal/Newspaper |
author |
Bassis, Jeremy N. Kachuck, Samuel B. |
author_facet |
Bassis, Jeremy N. Kachuck, Samuel B. |
author_sort |
Bassis, Jeremy N. |
title |
Beyond the Stokes approximation: shallow visco-elastic ice-sheet models |
title_short |
Beyond the Stokes approximation: shallow visco-elastic ice-sheet models |
title_full |
Beyond the Stokes approximation: shallow visco-elastic ice-sheet models |
title_fullStr |
Beyond the Stokes approximation: shallow visco-elastic ice-sheet models |
title_full_unstemmed |
Beyond the Stokes approximation: shallow visco-elastic ice-sheet models |
title_sort |
beyond the stokes approximation: shallow visco-elastic ice-sheet models |
publisher |
Cambridge University Press (CUP) |
publishDate |
2023 |
url |
http://dx.doi.org/10.1017/jog.2023.75 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143023000758 |
genre |
Ice Sheet Ice Shelf Journal of Glaciology |
genre_facet |
Ice Sheet Ice Shelf Journal of Glaciology |
op_source |
Journal of Glaciology page 1-12 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2023.75 |
container_title |
Journal of Glaciology |
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1 |
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12 |
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1792500927645614080 |